Pressurized fluid cylinders are used in various settings. For example, a self-contained breathing apparatus (SCBA) typically includes an air cylinder that is used to provide safe, clean air to an individual for breathing. An SCBA is configured to be worn by individuals, such as rescue workers, firefighters, and others, to provide breathable air in a hazardous or otherwise unsafe atmosphere. When configured for use underwater, an SCBA is typically referred to as a self-contained underwater breathing apparatus (SCUBA).
An SCBA typically includes a high-pressure tank (for example, 4,500 psi) that connects to a pressure regulator, which in turn connects an inhalation connection, such as a mouthpiece, mouth mask, or face mask. At least one of the tank, regulator, and inhalation connection may be secured to a carrying frame that allows an individual to carry the SCBA on his/her back, for example. After use, a fluid tank or cylinder needs to be re-filled for future use.
Various breathing air cylinders, such as SCBA and SCUBA, may be configured for a variety of filling pressures. For example, pressures such as 5500 psi, 4500 psi, 3000 psi, and 2216 psi. Known charge stations that are configured to refill breathing air cylinders may include a manual selector valve that allows an individual to choose a particular pressure. Many known charge stations only provide a choice of two pressures and are plumbed with numerous fittings and tubes. As such, known charge stations require significant training and experience in the part of the operator in order to correctly fill fluid cylinders that are configured to be filled to different pressures.
Further, known charge stations are typically unable to prevent an individual from filling a fluid cylinder to an incorrect pressure. For example, an individual may inadvertently and/or unknowingly fill a 4500 psi fluid cylinder to only 3500 psi, or over fill it to 5500 psi.
A known charge station includes parallel pressure regulators and pressure relief valves controlled by a manual selector valve. Such a system depends on an individual to select the correct pressure for a particular breathing air cylinder being filled. Another known charge station includes a single regulator that an individual adjusts for each pressure requirement. In either case, it is possible for the individual to improperly adjust the pressure setting. Further, the individual may set a pressure relief valve too high to protect the breathing air cylinders at the lower settings.